The Golden Jackal (Canis aureus) as a Reservoir of Toxocara spp.

Abstract

Recent large-scale expansion of the golden jackal (Canis aureus) across Europe has resulted in its rapid spread outside of its historic distribution and an increase in population. High adaptability to different habitats, opportunistic omnivorous feeding, climate change, changes in land use, and the absence of large predators are considered the main drivers for its spread. Golden jackal expansion has raised concerns about its potential role in disease dissemination, as this species is a host to numerous pathogens, including parasitic roundworms of the Toxocara genus. Domestic dogs and wild Canidae are definitive hosts for Toxocara spp., while many other species of animals, including humans, can be paratenic hosts. Toxocariasis is usually benign in adult definitive hosts but in others it can present with a variety of symptoms, ranging from mild to severe. Infection commonly occurs after ingestion of the roundworm’s eggs, which are excreted by definitive hosts, or larvae (L3), which reside in tissues of paratenic hosts. Toxocara spp. eggs are shed into the environment via feces of the definitive host, where they mature and become infectious. As with many other environmentally transmitted parasites, the eggs are highly resistant and remain viable for extended periods in soil and water, thereby increasing the odds for infection. While the infection is easily controlled in pets by administration of antiparasitic compounds, controlling infection in wildlife and in particular, preventing the spread of roundworm eggs in the environment is a daunting challenge. To evaluate the jackals’ importance as a reservoir of Toxocara spp., 69 digestive tracts of legally hunted animals were examined for the presence of the parasite. Toxocara spp. were recovered from 21.7% of jackals of which 46.7% were co-infected with tapeworms and/or other roundworms. These findings, together with the population growth dynamics and movement patterns of golden jackals, suggest a need for the development of surveillance programs for Toxocara spp. in areas with large jackal populations, while targeted control measures may need to be introduced in the future.